The present invention relates to a storage system and a data relocation control device.
The storage system is constituted by comprising at least one or more storage device, known as a disk array sub-system, for example. This storage device provides a storage region based on a RAID (Redundant Arrays of Independent Disks), wherein disk drives, such as hard disk drives, semiconductor memory drives, or the like, are arranged in an array configuration, for example. A host computer (hereinafter, called “host”) accesses the logical storage region provided by the storage device and reads or writes data.
The amount of data managed by businesses and organizations such as regional authorities, educational institutions, financial institutions, government and municipal offices, and the like, is growing steadily year on year, and storage devices are added and replaced as this data volume increases. As the data volume increases and the composition of storage systems becomes more complicated in this way, techniques have been proposed for improving the efficiency of use of storage systems by locating the data relating to various application programs, such as main management software and database management software, in suitable locations according to the value of that data (Japanese Patent Laid-open No. 2003-345522, Japanese Patent Laid-open No. 2001-337790, Japanese Patent Laid-open No. 2001-67187, Japanese Patent Laid-open No. 2001-249853, and Japanese Patent Laid-open No. 2004-70403.)
The respective reference patents mentioned above disclose techniques for relocating data by copying data stored in one volume to another volume, on the basis of disk performance information and use information.
However, in the techniques described in these references, it is necessary to relocate data individually, in volume units, and the user is not able to move volumes between freely defined layers, and hence usability is poor. Moreover, in the techniques described in the aforementioned patent references, since data is relocated in volume units, it is difficult to relocate data in a group of related volumes, together, in one operation. Furthermore, the techniques described in the aforementioned patent references focus exclusively on the relocation of the data, and do not give consideration to the processing after relocation of the data. Therefore, usability is poor from this viewpoint also.